Tim Sperry spent nearly 25 years as an executive at Whole Foods and was a key figure in the company’s ascent from a small grocery chain to a household name and natural foods powerhouse. Eleven years removed from his role as the company’s director of grocery, Sperry is concerned that Whole Foods’ merchandising prowess and brand identity have fallen into neglect -- and he’s not alone. The retailer has lost some of its luster with customers, suppliers and investors, and the news is filled with talk of